{keyword}) Union All Select Null,null,null,null,null-- Zkhd 📢

: The original table has exactly 5 columns. This confirms a vulnerability and allows the attacker to move to the next step: identifying which columns can display sensitive data.

: The attacker uses a specific number of NULL values to match the number of columns in the original query's SELECT statement. NULL is used because it is compatible with almost any data type (strings, integers, dates), maximizing the chance that the injected query will succeed. {KEYWORD}) UNION ALL SELECT NULL,NULL,NULL,NULL,NULL-- ZkhD

: This is likely a random string or a "signature" used by a vulnerability scanner (like Burp Suite or sqlmap) to track if the payload was successfully reflected in the application's response. : The original table has exactly 5 columns

: The number of NULL values (5 in this case) does not match the number of columns in the original table. NULL is used because it is compatible with